westcott



(fio Model.) J; H. WESTCOTT.

. I I If I I I I. I I fiu I I I I I n r I. I I I. I

LATHE CHUCK UNITE arena? tribe. 3

JOHN H. \VESTOOTT, OF ONEIDA, NEW YORK.

LATHE-CHUCK.

SPECIFICATION forming part of Letters Patent No. 335,982, dated February 9, 1886.

Application filed December 4, 1885. Serial No 184,678. (No model.)

To all whom it may concern.-

Be it known that I, JOHN H. Wnsrcorr, of Oneida, in the county of Madison, in the State of New York, have invented new and useful Improvements in Lathe-Ohucks, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description.

Experience has proven that the majority of lathe chucks which have the jaw guiding grooves extending completely across them are so weakened by said grooves as to render them liable to spread and lose their requisite firm hold on the jaws when the tool or other obr 5 ject held by the jaws is subjected to the opera tion of cutting or abrading.

The object of my present invention is to obviate the aforesaid defect; and to that end my invention consists in the application to the chuck-head of extra stays for sustaining the jaws independently of their adjusting devices, and also in a novel construction and combination with the chuck'hcad of a tie-plate extending across the jaw-guiding grooves of the chuck-head, and provided at opposite sides of said grooves with shoulders engaging corresponding shoulders on the chuckhead; and it furthermore consistsin anovel combination of the aforesaid stays and tie-plate with the chuck-head, all as hereinafter more fully explained, and specifically set forth in the claims.

In the accompanying drawings, Figure I is a side view of my improved chuck. Fig. II is a face view thereof. Fig. III is a transverse section on line a: 00, Fig. II. Fig. IV is a face view of the chuck-head without the tie-plate, and Fig. V is a view of that side of the tieplate by which it is seated on the chuck-head.

Similar letters of reference indicate corresponding parts.

A denotes the chuck-head, which is provided with the diametric groove 11, constituting two radial grooves, in each of which is guided one of the jaws B. A right-and-left screw, D, extending through the chuck-head and engaging with corresponding screwthreads on the jaws serves to adj nst said jaws so as to grip the tool or work.

The foregoing is the ordinary and wellknown construction, and requires no detail description here, especially as I do not limit my invention to any particular form of jaws or means for adjusting the same. The face of the chuck-head A, I provide with straight shoulders a a, extending across the chuckhead at opposite sides of and parallel with the jaw-guiding grooves n.

I? represents a tic-plate, which is mounted on the face of the chuckhead, movable parallel with the jawguiding grooves n by means of screws 0 e, passing through slots (Z d in the plate P, and entering screw-threaded sockets in the chuck-head, the slots d (I being parallel with the groove n, to allow the plate P to move in the direction aforesaid. The plate I? is also provided with a slot, 3, coinciding with the grooves a, and terminating with ties it, which are parts of the plate extending across the grooves aback of the jaws B B. The side of the plate P adjacent to the chuck-head is provided with parallel shoulders b 1), extending across the plate and coinciding with the shoulders a a, which they embrace between them, and thus afford a secure hold for the plate I on the chuclchead, so as to effectually prevent the latter from spreading. The parts of the plate B forming the sides of the slot 3 abutting against opposite sides of the jaws serve to brace the latter at right angles to their guide-groove. The lateral strain on the jaws, instead of being transmitted to one side of the guide-groove a, is resisted by the engagingshoulders to and I) back of the opposite side of said groove.

ff represent set'screws extending through correspondingly screw-threaded holes in the ties t t, and bearing with their inner ends against the backs of the jaws B B, as best seen in Fig. II of the drawings. These setscrews serveto sustain the jaws independently of the adjusting-screw D or other adjusting device. Since the plate I is arranged movably on the chuck-head, the set-screws can be firmly set up against the jaws without danger of disturbing them from their concentricity with the chuck-head, and the chuck-head is entirely relieved from any strain that maybe exerted on the jaws in a direction parallel with the guide-grooves thereof. I do not, how ever, limit myself to the use of the aforesaid setscrews, as it is obvious that keys or gibs or compensating blocks may be interposed between the ties t t and backs of the jaws, to serve as stays for said jaws. Neither do I limit myself to the use of two of the aforesaid set-screws, inasmuch as one of them may be dispensed with.

Having described my invention, what I claim is 1. The combination, with the chuck-head, and jaws adjustablyconnected therewith, of extra stays applied to the back of the jaws, to sustain the same independently of their adjusting devices, as set forth.

2. The combination, with the'chuck-head having radial grooves, and jaws in said grooves, of a plate secured to the chuck-head, movable parallel with the jaw-guiding grooves, and extending across said grooves back of the jaws, and adjustable stays interposed between the back of the jaws and adjacent parts of the plate, substantially as and for the purpose specified.

3. The combination of the chuck-head having ladial grooves, and jaws in said grooves, and the shoulders or a at opposite sides of and parallel with the said grooves, the plate P, mounted movably on the chuck head, and

having parallel shoulders I) b, embracing between them the shoulders a a, and provided with the slot 8, terminating with ties t t, and abutting with the sides of the slot against the sides of the jaws, and adjustable stays interposed between said ties and back of the jaws, substantially as described and shown.

4. The combination of the chuck-head having radial grooves, and jaws in said grooves,

and the shoulders at a at opposite sides of and parallel with the grooves thereof, the plate P, having the slots, terminating with ties t t, and provided with slots at d and with shoulders I) b, the attaching-screws e e, passing through the slots d d, and the set-screws f f, inserted in the ties and bearing against the back of the jaws, substantially as described and shown.

In testimony whereot'I have hereunto signed my name and affixed my seal, in the presence of two attesting witnesses, at Syracuse, in the county of Onondaga, in the State of New York, this 28th day of November, 1885.

JOHN H. WESTGOTT. [L. s] Witnesses: v

O. CARSKADDAN, H. SKINNER. 

